Sometimes you feel like a nut... sometimes you don't

I recently heard from a reader in Florham Park who was struggling with a good idea gone bad.

When he and his wife moved to their quarter-acre plot 40 years ago, they bought into an idea that was making the rounds: that planting black walnut trees was a good investment with a big future payoff.

Everybody knows walnut lumber is sought-after and valuable, right? All it takes is a few decades to grow the trees into a mature cash crop, right?

Those innocent-looking little seedlings are big trees now, and a few problems have surfaced. For one thing, they are producing nuts by the truckload.

"The fruit comes down in torrents," writes my correspondent. "This past season it was impossible to walk in the treed area unless you were wearing a protective helmet."

Well, that's a fine kettle of fish, as Oliver Hardy used to say. Being strafed by your own landscaping is like something straight out of scary fairy tale. And there aren't enough squirrels, deer and woodpeckers in all of Florham Park to make a dent in the crop.

But what about this idea that you can get big bucks for your walnut trees? Unfortunately, this is rarely true for walnuts grown in an urban setting -- and without the corrective pruning that would produce a branchless, straight trunk.

The most readily marketable trees have a trunk height of at least eight to 10 feet from the base to the first branch or tree fork, and a diameter of at least 18 inches measured at a point 4½ feet from the ground.

This is hard to achieve if the trees have not been thinned and pruned since childhood. In an urban environment, where trees are not competing for light as they do in a plantation setting, they usually branch low to the ground and therefore don't have much in the way of a clear trunk.

Defects are another thing to consider. Those who might use the lumber for furniture or gun stocks are looking for trunks free of holes, bumps, cracks, scars, wounds and insect or disease damage. Foresters may know how to fend off these defects, but the average homeowner probably would not.

The most valuable trees are those that can be cut for veneer, thin layers of walnut that can be applied to other, cheaper woods for a high-end look. This presents another problem for the backyard grower. Purchasers will rarely take an urban tree for veneer because it might have foreign objects -- eye bolts for a hammock, brackets for a bird feeder -- that could cause injury to anyone felling the tree and processing it.

The current owner may have no knowledge of any such hardware, but veneer-makers are unlikely to take the chance. Not only would these foreign objects diminish the value of the tree, but they could cause serious damage to the sharp, spinning blades of the expensive equipment that cuts veneer sheets from the trunk.

Finally, walnut-buyers are reluctant to harvest just a few trees, especially in an urban setting. They don't want to deal with the tight quarters, overhead power lines and other obstructions that add to the labor costs of felling the trees and carting them away.

The best use for most urban walnuts that have to come down may be firewood -- the wood burns easily. And the greatest gain is often the profit realized by the tree company that removes the tree for you. It can cost several hundred to more than a thousand dollars to cut down a mature backyard walnut tree, quite a reversal of fortune for the homeowner hoping to realize some cash.

Do walnuts at least make good landscape subjects? Well, along with all those nuts, there is another downside. Black walnuts produce a toxic substance in their roots, juglone, that is poisonous to many other plants. Even walnut leaves, bark and wood (or mulch) can cause injury in such landscape plants as azalea, rhododendron, crabapple, lilac, pine and peony -- and are death to tomatoes, eggplants and peppers.

So, that walnut in the backyard is not only unlikely to pay for the kid's college tuition, but can also thwart your landscape plans and kill whatever is planted near its root zone. And it will pelt you with more walnuts than any cook could use in a lifetime of coffee cake, strudel and ice cream sundaes.

The notion that one who plants a walnut will prosper seems to be an urban legend, quite untrue on further examination. It's another promising idea gone south. Don't you hate that?
Valerie Sudol's "Garden Diary" column appears every Thursday in The Star-Ledger. To reach Valerie, write to The Star-Ledger, 1 Star Ledger Plaza, Newark, N.J. 07102-1200 or e-mail her here.